Robot Cleaner Light Pattern Discrimination for Reflection-Free Mapping
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Solution Overview
Problem
Existing robot cleaners face challenges in distinguishing between light patterns projected for navigation and those generated by light reflections from floors or objects, which can interfere with accurate area mapping and obstacle detection.
Innovation Solution
A method for controlling robot cleaners that involves projecting light patterns and acquiring images to discriminate between direct and reflected light patterns using geometrical characteristics, defining a reference position for valid patterns, and updating this position based on distance and pattern alignment to accurately map the environment and detect obstacles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If light patterns are projected for navigation and area mapping, then the robot cleaner can autonomously move and identify cleaning areas, but reflected light patterns from floors or objects interfere with accurate pattern detection and analysis
Solution Approach 1:
The patent segments the detected light patterns into two distinct categories: direct light patterns (valid for navigation) and reflected light patterns (to be filtered out). By applying geometric analysis based on the known projection direction and optical axis direction, the system separates valid patterns from invalid reflected patterns, enabling accurate detection while maintaining autonomous navigation capability
Solution Approach 2:
The patent introduces geometric characteristics as an intermediary criterion to distinguish between direct and reflected light patterns. By using the angular relationship between the projection direction and optical axis as a filtering mechanism, the system enables the camera to accurately identify valid patterns while rejecting reflected light interference
2Loss of information
If the robot cleaner uses a camera to photograph the area to which light is projected, then it can recognize the state of the cleaning area, but it cannot distinguish between direct light patterns and reflected light patterns from the captured image
Solution Approach 1:
The patent performs preliminary geometric analysis by defining the projection direction of the light source and the optical axis direction of the camera before pattern detection. This pre-established geometric framework enables the system to automatically distinguish direct from reflected light patterns during image processing, facilitating accurate cleaning area state recognition without additional hardware complexity
Solution Approach 2:
The patent changes the analysis parameter from simple pattern presence detection to geometric parameter analysis (angular relationship between projection direction and optical axis). By evaluating the geometric characteristics of detected patterns, the system can differentiate between direct and reflected light patterns, resolving the discrimination difficulty while maintaining information recognition capability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the robot cleaner to effectively differentiate between direct and reflected light patterns, improving its ability to map the cleaning area and detect obstacles, leading to more accurate navigation and efficient cleaning operations.
Implementation Method 1
a pattern projection unit for projecting light in a predetermined pattern toward a floor of an area in front of the main body of the robot cleaner, and a camera for photographing the area to which the light is projected
Implementation Method 2
since some materials of floors or objects to which light is projected reflect the light, a new light pattern due to reflection can be detected in addition to the original light pattern
Data Source
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AI summary
A method for controlling a robot cleaner configured to project light of a predetermined pattern to a floor of an area in front thereof in a specific direction and to acquire an image of the area to which the light is projected, according to the present invention, includes: (a) acquiring a front view image of the robot cleaner; (b) detecting the pattern from the image acquired in (a); and (c) discriminating a pattern formed by reflected light from a pattern formed by light directly projected from the robot cleaner, from among patterns indicated in the acquired image, on the basis of geometrical characteristics defined by a projection direction of the light and the direction of an optical axis in which the image is acquired when two or more patterns are detected from the image.